Energy Values of Maize Silages, Harvested and Ensiled at Different Seasons, With Nylon Bag and Enzymatic Methods

Abstract

Energy values of maize silages harvested and ensiled at before silking (BS), silking (S), milk line (ML) and half milk line (HML) were determined by nylon bag and enzyme (pepsin-cellulase) methods. In the nylon bag technique, dry matter (DMD) and organic matter digestibility (OMD) of maize silages (60.02 and 65.63% BS stage) were reduced by advancing maturity stage. In the enzyme method, when DMD of maize silages (55.24% at BS stage) was reduced, OMD (42.20%) was increased by advancing maturity stage (P<0.05). Determined DMD and OMD values with nylon bag technique as well as digestible (DE), metabolizable (ME) and net energy for lactation (NEl) method were higher than the enzyme method (P<0.01). According to the linear regression analysis, relationships between two methods were nonsignificant. But the results of 2(nd) degree polynomial function regression analyses, all relationships were significant and the highest R-2 value was 0.63 for following equation: Nylon bag organic matter digestibility=62.79-22.99STAGE+0.014EME+3.99STAGE(2)-0.0001EME(2). Thus enzyme method could be used only at milk line for estimations of DMD, OMD, DE, ME and NE1.